1. Field of the Invention
The present invention relates to a septic tank. In particular, the present invention relates to a septic tank for treating household waste water including human feces in daily life.
2. Description of the Related Art
Household waste water containing human feces is firstly collected in a septic tank in a basement of a building. Cleaner waste water after purification is discharged to adjacent water discharge pipes to avoid contamination to drinking water and the environment. The decayed and deposited sludge in the septic tank is removed when it is accumulated to a certain amount.
For efficient purification of the waste water to be discharged, the septic tank is divided into several chambers including a decomposing chamber, a filtering chamber, and a deposit chamber that are separated from one another by partitioning walls. A waste water inlet pipe is mounted at a higher level of the first chamber, and a waste water outlet pipe is mounted at a lower level of the last chamber. A stirring device may be mounted in the decomposing chamber to break the feces for speeding up decomposition. When the waste water containing feces enters the septic tank, it is purified after separation and deposition before it is discharged via the outlet pipe.
However, each chamber of the multi-chamber type septic tank is much smaller than a septic tank having a single chamber. As a result, blocking and overflowing are apt to occur. Further, it is difficult to install the stirring device due to hinder by the partitioning walls separating the chambers.